Patent GB-659060-A (GB)
Title: Lamp sealing apparatus
IPC: H01J5/24
Filed: 1947-08-05
Abstract: 659,060. Machines for making tubular electric lamps. SYLVANIA ELECTRIC PRODUCTS, Inc. Aug. 5, 1947, No. 21279.. Convention date, Dec. 9, 1941. [Class 39(ii)] A turret machine for sealing an elongated glass tube to a glass mount, as in the manufacture of fluorescent lamps, comprises a series of heads each carrying a mount support and a support for the glass tube above and in register with the mount support, with a burner located below and concentric with the mount support and disposed to direct a cone of flame radially outward and upward, and a sealing ring concentric with the burner and movable vertically thereon by automatic means which raises the sealing ring to compress the mount and end of the glass tube subsequent to heating and softening, the said automatic means being adapted to exert on the work a predetermined compressing force. A support 48 for a burner 47 is mounted at the forward extremity of each of the heads 1 around the turret, the burners being connected by pipe lines 28 to the lower plate 25 of a pair of superposed valve plates 24, 25 in which gas, air and oxygen are mixed, the upper valve plate 24 being connected to inlet pipes for the respective gases. Each head 1 is provided with a pair of jaws 36, 37 pivoted on the ends of arms 38, 39 and arranged to be opened to receive and release a tube 2 under the action of a vertical cam shaft 14, Fig. 2, provided at its lower end with a lever 15 carrying a roller 16 which engages a stationary cam track 11 located on an annular table 82 surrounding the turret. The upper end of the tube 2 is held by a vertically adjustable clamp 23, 29. A peripheral cam track 6 provides means for elevating the sealing-ring 50, Fig. 3, associated with each head, and pushes it up to ensure accurate seating and alignment of the mount, which is supported on a frusto-conical mount-pin 45 above the burner 47. After the glass has been softened the sealing.ring is pushed upwardly by pressure on its vertical supporting shaft 51 which is contacted by a vertical push rod 52, Figs. 1 and 4, on a lever arm 55 which .is secured on a horizontal shaft 57 arranged to be rocked by a link 61 and bell-crank 63 operated by .a cam 60. The push rod 52 is slidably mounted on the lever arm 55 and surrounded by a helical compression spring 53 designed to transmit sufficient pressure to compress the heated rim of the mount and neck of the tubular envelope. As shown, the cam 60 is mounted on one end of a shaft 80 the other end of which carries a cam 68 operating the mechanism associated with duplicate sealing devices on the opposite side of the turret. A mount may thus be sealed at each end of a lamp tube during a single revolution of the turret, it being necessary to remove and invert the tube relative to its holder after half a revolution, the mount supports on one side of the turret being adapted to receive a mount provided with an exhausting-tube while those on the other side, by means of a peripheral lip on the conical surface of the mount support, provide accurate seating for a mount without an exhausting-tube. The valve. sturcture comprising the valve plates 24, 25 controlling the admission of the combustible gases to the burners is substantially similar to that described in Specification 625,409.